2 Visual Components Manuals

This is not required for normal Visual Components operation and should only be done in conjunction with your
relevant B&R support contact or application technician. The necessary parameters, along with their values, are
listed here in case they are needed.
3.3.8.30.1 Parameter
I/O Parameter Type Meaning
IN enable BOOL This function is only executed if enable is TRUE.
IN VCHandle UDINT The handle returned by VA_Setup.
IN Type USINT
IN Parameter UDINT New parameter string
Type of driver whose parameters should be changed
1 Display driver
2 Key driver
4 Touch driver
OUT Return Value UINT Not equal to 0 if error occurs
The project may not be run while changing driver parameters. The correct sequence for changing driver
parameters is as follows:
• Stop the project with VA_StopProject
• Change the driver parameter(s) with VA_SetUserParam
• Start the project with VA_StartProject
3.3.8.31 Shutdown − VA_Shutdown
This function is no longer used in the current version of the Visapi library (V2.3), but wasn't removed from the
library itself for compatibility reasons. We recommend not using this function anymore in new projects.
The VA_Shutdown function should only be executed before a project is started.
3.3.8.31.1 Parameter
I/O Parameter Type Meaning
IN enable BOOL This function is only executed if enable is TRUE.
IN VCHandle UDINT The handle returned by VA_Setup
OUT Return Value UINT Not equal to 0 if error occurs
3.3.8.32 Requirements and Initialization − VA_Srelease
The VA_Srelease function must always be called at the end of a VISAPI function in a cyclic task. Otherwise, no
more VA_Saccess functions can be called.
3.3.8.32.1 Parameter
I/O Parameter Type Meaning
IN enable BOOL This function is only executed if enable is TRUE.
IN VCHandle UDINT The handle returned by VA_Setup
OUT Return Value UINT Not equal to 0 if error occurs
3.3.8.32.2 Example for Automation Basic
(* cyclic program *)
if ready 1 then
VC_HANDLE = VA_Setup(1 "vga") ,
VC_HANDLE if 0 then
ready = 1
endif
endif
if ready = 1 then
if VA_Saccess(1,VC_HANDLE)= 0 then
VA_Srelease(1,VC_HANDLE)
Introduction to Visual Components 2.3
166 3.3.8.30 Manual Project Control − VA_SetUserParam